require_settings.py

# https://gist.github.com/bryanchow/d30c0c7021f93b416744

from django.conf import settings
from django.core.exceptions import ImproperlyConfigured


def require_settings(*args):
    """
    Check django.settings for the presence of the specified keys. Accepts
    settings keys as function args, or as a list of strings.

    Usage:
        require_settings('SITE_URL', 'DEFAULT_DOMAIN')
        require_settings(['SITE_URL', 'DEFAULT_DOMAIN'])
    """

    if len(args) == 1 and not isinstance(args[0], str):
        args = args[0]

    for key in args:
        if not hasattr(settings, key):
            raise ImproperlyConfigured(
                "{} not defined in settings".format(key)
            )